|Season|A Technical|B Scientific|C Fine Arts|D Improvisational|E Structural|Rising Stars!®|pO projectOUTREACH®|University Level|
|---|---|---|---|---|---|---|---|---|
|2014-2015|Creature Feature|Making Waves|Feary Tales|The Improv Games|Lose to Win|Animal Mish Mash|Brand Aid|It's a Stretch|
|2013-2014|Dig In|Going to Extremes|Laugh Art Loud|Pandemonium!|The Tension Builds|Circus!|Pitch and Play||
|2012-2013|In the Zone|Windvisible|In Disguise|Change in RealiTEE|twist-o-rama|ROY G BIV|Real to Reel||
|2011-2012|Assembly Required|The Solar Stage|Coming Attractions|News To Me|Hold It!|Built to Last|The World Canvas||
|2010-2011|Unidentified Moving Object|Spinning a Tale|Triple Take Road Show|Mythology Mission|Verses! Foiled Again!|Big Bug's Bad Day|Dynamic Networks||
|2009-2010|DIrect DIposit|DI-Bot|You’re Gonna Flip!|Do or DI|Breaking DI News|Weighty News|Band Together||
|2008-2009|Operation Cooperation|Instinct Messaging|ViDIo Lit Hits|Private DI|A New Angle!|Hidden!|Take Charge||
|2007-2008|Obstacles, Of Course!|Hit or Myth|DI've Got a Secret!|Chorific!|SWITCH!|TwisDId History|||
|2006-2007|DIrect Flight|CSI-DI|Round About Courage|Switching TraDItions|Card-DI-ology|Make It New, It's Up To You|||
|2005-2006|Back At You!|Kidz Rulz!|How’d tHAT Happen?|On Safari|The Inside DImension|1-2-Change-A-ROO|||
|2004-2005|DIzzy Derby|Sudden SerenDIpity|Live! It's RaDIo DI!|IMPROVing Along|DIsigning Bridges|More to the Story!|||
|2003-2004|Destinations in Time|The Plot and the Pendulum|Cartoon DImensions|Upbeat Improv|GuessDImate!|Surprise Trip!|||
|2002-2003|Change in DIrection|ViDIo Adventure|Theatre Smarts|Once Improv A Time|ConnecDId|Lost and Found|||
|2001-2002|It's Your Move|StranDId|On Holiday|The Art of Improv|Dual DI-lemma||||
|2000-2001|IncreDIble TechEffects|Mystery Loves Company|Anonymously Yours|DInamic Improv|Triplicity||||
|1999-2000|Fruit Roller Coaster & Eggploration|If Music Be the Food of Life... Play on!|Mixing Apples and Oranges|Instant Pudding Improv|It's Not Impastable!||||

Question: how many more challenges were there in 2014-2015 than in 2006-2007?
Answer: 2